Detection system and method between accessory and electronic device

ABSTRACT

Accurate and reliable techniques for determining information of an accessory device in relation to an electronic device are described.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. 119(e) to U.S.Provisional Patent Application No. 61/681,117, filed Aug. 8, 2012 andentitled “Consumer Electronic Product” by Sartee et al., and U.S.Provisional Patent Application No. 61/657,693, filed Jun. 8, 2012 andentitled “Smart Cover Peek” by Zambetti, each of which is hereinincorporated by reference in its entirety.

FIELD OF THE DESCRIBED EMBODIMENTS

The described embodiments generally relate to accessory devices usedwith portable electronic devices. More particularly, the presentembodiments describe passive and active circuits that can be usedindividually or in combination to identify specific characteristics ofthe accessory device. The identified characteristics can be used by theportable electronic device to alter an operating state of the electronicdevice, identify specific features of the accessory device, and soforth.

DESCRIPTION OF THE RELATED ART

Recent advances in portable computing includes the introduction of handheld electronic devices and computing platforms along the lines of theiPad™ tablet manufactured by Apple Inc. of Cupertino, Calif. Thesehandheld computing devices can be configured such that a substantialportion of the electronic device takes the form of a display used forpresenting visual content leaving little available space for anattachment mechanism that can be used for attaching an accessory device.

The display can include various user interface features that caninteract with external stimuli to convey information from an end user,for example, and processing circuitry in the hand held computing device.For example, the display can include touch sensitive elements that canbe used to enable various multi-touch (MT) functions. When the accessorydevice takes the form of a cover, the handheld computing device can beoperable in modes consistent with the presence of the cover. Forexample, when the handheld computing device has a display, the presenceof the cover can render the display unviewable. In order to save power,the unviewable display can be rendered temporarily inoperable until thecover is moved or otherwise repositioned to expose the display.

Therefore, accurate and reliable techniques for determining selectedaspects of an accessory device are desired.

SUMMARY OF THE DESCRIBED EMBODIMENTS

This paper describes various embodiments that relate to a system,method, and apparatus for passively providing information from anaccessory device to a host device. In one embodiment, the accessorydevice takes the form of a protective cover and the host device takesthe form of a tablet computer.

In one embodiment, accessory device is described. The accessory deviceincludes at least a flap where the flap includes at least a passiveinformation element associated with accessory device information. Theaccessory device also includes an attachment mechanism configured forreleasably attaching the accessory device and an electronic device. Inthe described embodiment, the electronic device includes a processor, adisplay, an attachment detection mechanism configured to detect that theaccessory device is attached to the electronic device, and a passiveinformation detection mechanism that is enabled to (1) detect thepresence of the passive information element, and (2) receive informationfrom the passive information element only when the attachment detectionmechanism provides an indication that the accessory device and theelectronic device are attached to each other.

In another embodiment a method for altering an operating state of anelectronic device in accordance with accessory device informationassociated with an accessory device is described. The method is carriedout by performing at least the following operations: detecting thepassive information element by a detection mechanism in the electronicdevice, determining the accessory device information based upon thedetecting, and altering the operating state of the electronic device inaccordance with the accessory device information.

Non-transitory computer readable medium for altering an operating stateof an electronic device having a processor and a display are described.The computer readable medium includes at least computer code fordetecting the passive information element by a detection mechanism inthe electronic device, computer code for determining accessory deviceinformation based upon the detecting of the passive information element,and computer code for altering the operating state of the electronicdevice in accordance with the accessory device information.

In yet another embodiment, an accessory device is described. Theaccessory device includes an attachment mechanism for attaching theaccessory device to an electronic device having a display and aprocessor. The accessory device includes at least a flap having a sizeand shape in accordance with the display and an information element. Inthe described embodiment, the information element is associated withaccessory device information such that when the information element isdetected by a detection mechanism in the electronic device. Thedetection mechanism provides the accessory device information to theprocessor. The processor uses the accessory device information to alteran operating state of the electronic device. Generally, the detectionoccurs only when the flap and the display are in close proximity to eachother.

Other aspects and advantages of the invention will become apparent fromthe following detailed description taken in conjunction with theaccompanying drawings which illustrate, by way of example, theprinciples of the described embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like structural elements, and in which:

FIG. 1 shows a top perspective view of an electronic device inaccordance with the described embodiments.

FIG. 2A shows a first perspective view of the electronic device in theform of a tablet device and the accessory device in the form of aprotective cover.

FIG. 2B shows a second perspective view of the electronic device in theform of a tablet device and the accessory device in the form of aprotective cover.

FIG. 3A shows a closed configuration of the cooperating system formed bythe tablet device and protective cover shown in FIGS. 2A and 2B.

FIG. 3B shows an open configuration of the cooperating system shown inFIG. 3A.

FIG. 4 shows a top view of an embodiment of a segmented cover assembly.

FIG. 5 shows a top view of another embodiment of protective cover 200 inthe form of cover assembly.

FIG. 6A and FIG. 6B shows a segmented cover in partial openconfigurations with respect to a tablet device and FIG. 6C shows asegmented cover in a partial open configuration.

FIGS. 7A and 7B illustrates tablet device in a first peek mode and asecond peek mode, respectively, in accordance with the describedembodiments.

FIG. 8 shows system that includes protective cover pivotally coupled totablet device in accordance with the described embodiments.

FIG. 9 shows system being a more generalized version of system 800 inwhich various information elements are shown.

FIG. 10 shows a flowchart detailing process in accordance with thedescribed embodiments.

FIG. 11 shows a flowchart detailing process in accordance with thedescribed embodiments.

FIG. 12 shows a flowchart detailing process in accordance with thedescribed embodiments.

FIG. 13 shows state peek mode state diagram in accordance with thedescribed embodiments.

FIG. 14 shows a flowchart detailing process in accordance with thedescribed embodiments.

FIG. 15 shows a flowchart detailing process in accordance with adescribed embodiment

FIG. 16 is a block diagram of an electronic device suitable for use withthe described embodiments.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

Reference will now be made in detail to representative embodimentsillustrated in the accompanying drawings. It should be understood thatthe following descriptions are not intended to limit the embodiments toone preferred embodiment. To the contrary, it is intended to coveralternatives, modifications, and equivalents as can be included withinthe spirit and scope of the described embodiments as defined by theappended claims.

The following description relates in general to a mechanism that can beused to identify characteristics of an accessory device used with anelectronic device having a display. The display can be configured topresent visual content. In some cases, the display can include a touchsensitive layer configured to sense externally applied stimuli, such asa touch event, and in response, provide information that can be used bythe electronic device. For example, the display can include capacitivebased multi-touch (MT) functionality well suited for recognizingconcurrently applied multiple input events In a particular embodiment,the accessory device takes the form of a protective cover. Theprotective cover can include a flap pivotally connected to a hingemechanism. The hinge mechanism, in turn, can include an attachmentmechanism for releasably attaching together the protective cover and theelectronic device. The flap can have a size and shape in accordance withthe display. In this way, when coupled with the tablet device, the flapcan rotate about the hinge portion in a first direction to bring theflap in substantial contact with the display in a closed configuration.Conversely, the flap can pivot about the hinge assembly in a seconddirection opposite the first direction to expose the display, or aportion thereof, in an open configuration. In one embodiment, theelectronic device can take the form of a tablet device.

The protective cover can provide protection to certain aspects (such asthe display) of the tablet device while enhancing the overall look andfeel of the tablet device. The protective cover can include electroniccircuits or other elements (passive or active) that can cooperate withelements, electronic or otherwise, in the tablet device. As part of thatcooperation, signals can be passed between the protective cover and thetablet device that can, for example, be used to modify operations of thetablet device, operations of electronic circuits or elements of theprotective cover, and so forth. The signals can also be used to evaluatecertain aspects of the protective cover. For example, the protectivecover can include an object, or objects, that can be detected bycorresponding elements disposed within the tablet device. The object(s)can provide information to the tablet device that can be used toidentify certain aspects of protective cover, such as color, style,owner, etc. The objects can be passive or active. For example, passiveelements can take the form of magnets and capacitive elements, whereasactive elements can take the form of RFID tags, near field communication(NFC) elements, wireless elements (such as Bluetooth™), and so forth.

The electronic device can include a number of sensors. These sensors caninclude at least a number of different types of magnetic sensors. Forexample, a Hall Effect sensor (HFX) can simply detect a presence of amagnetic field providing information along the lines of ON/OFF, “0”,“1”, and so forth. In addition to using a number of magnets to encodeinformation, polarities of the magnets can be used to encodeinformation. For example, when the protective cover has n magnetsdetectable by a corresponding magnetic sensor disposed in the tabletdevice that can discern magnetic polarity, there can be 2″ bits ofinformation magnetically encoded in the protective cover. In aparticular embodiment, the number n of magnets can be four in whichcase, the total number of information bit is also four representing a 2⁴or 32 information states. The 32 information states can includeinformation related to specific aspects of the protective cover such ascolor, style, owner information, purchase date, and so forth.

A linear Hall Effect sensor can be used to sense the motion, position,or change in field strength of a magnet. Differences in the magneticfield strength detected by the linear Hall Effect sensor can be used toevaluate a current status of the protective cover with respect to thetablet device. For example, a change in detected magnetic field strengthvalue can indicate that a change in the tablet device/protective coverattachment status has changed or that a relative distance between themagnet and the linear Hall Effect sensor has changed. This change inrelative distance can indicate that the protective cover has movedrelative to the tablet device. For example, a linear Hall Effect sensormeasuring a relative change in magnetic field strength value of 5milli-Tesla (mT) can indicate that the protective cover has moved to amore open position or a more closed position relative to the tabletdevice. It should also be noted that monitoring the magnetic fieldstrength value in real time (or sampling) can indicate motion of theprotective cover in relation to the tablet device. In this way, motionof the protective cover with respect to the tablet device can bedetected as well as the direction of the motion of the protective coverin relation to the tablet device.

In order to enhance the affect of magnets in either the tablet device orthe protective cover, certain magnets can be arranged as a magneticarray. One such magnetic array can take the form of a Halbach array. TheHalbach array can be construed as a one side magnetic flux structurehaving an augmented magnetic field on one side of the Halbach array anda magnetic field near zero on an opposite side of the Halbach array.This effect can be realized by arranging a number of permanent magnetsin a spatially rotating pattern of magnetization. In this way, using theHalbach array to provide an augmented one sided magnetic field canimprove magnetic attachment between the protective cover and the tabletdevice or the detectability of the resulting augmented magnetic field.

In some embodiments, components disposed within or on the protectivecover can be used to determine a relationship between the protectivecover and the tablet device. For example, when the cover includesmagnets (for attachment purposes, information signaling purposes, etc.),these magnets can affect magnetically sensitive circuits (such as amagnetometer used in some cases as a magnetic compass) disposed in anadjoining tablet device that can be used as a signal. This signal can,in turn, be used to deduce a spatial relationship between the protectivecover and the tablet device. For example, when the tablet deviceincludes a magnetic circuit in the form of a magnetic compass, magnetsin the protective cover can cause the magnetic compass to experience amagnetic offset (a deviation from a baseline compass direction) having amagnetic offset value (generally expressed in degrees, “x^(o)”).Accordingly, the magnetic offset value can be used to deduce arelationship between the protective cover and the tablet device. Anobserved magnetic offset value can be correlated to a known tablet/coverconfiguration, such a magnetically attached, fully open configuration,fully closed configuration, or partially open configuration. In somecase, it may be desirable to recalibrate the magnetic compass based uponthe spatial relationship between the cover and the tablet device. Forexample, when the cover is fully open the affect of magnets in the coveron the magnetic compass can be minimal, however, as the cover is broughtcloser to a fully closed position and the compass remains viewable (suchas in peek mode), then the affect of the magnets can be greaterrequiring a re-calibration of the magnetic compass.

Sensors can also be used to determine an angular displacement of theprotective cover and the tablet device. For example, the linear HallEffect sensor can be used to detect an angular displacement of a magnetin the cover with respect to the linear Hall Effect sensor. The angulardisplacement can be correlated to magnetic field strength (measured inmilli-Tesla, or MT, for example) detected by the linear Hall Effectsensor and any changes in the detected values can be associated with achange in a spatial relationship between the tablet device and theprotective cover. The change in spatial relationship can includepivoting of the cover away or towards the tablet device.

In another embodiment, when the tablet device includes an opticalsensor, such as an image capture device such as a camera or ambientlight sensor (ALS) for detecting ambient light levels in vicinity of thecamera, information can be encoded by the protective cover usingoptically sensitive indicia. For example, the protective cover caninclude openings suitably sized and located that permit selected amountsof light to penetrate through the protective cover. For example, apattern of micro-perforations can be formed in the protective cover thatalthough not discernible by a user can nonetheless allow sufficientlight to reach an optical sensor in line with the micro-perforations. Inthis way, the pattern of light reaching the optical sensor can provideinformation that can be used by the tablet device. In some cases, thepattern of micro-perforations can be akin to a bar-code providinginformation specific to the protective cover. Such information caninclude serial number, style, color, and so forth. In one embodiment,the ALS can include a photosensitive circuit (such as a photodiode) thatcan respond to varying levels of incident light, typically in the formof ambient light. The optical sensors can also be sensitive to lightbeyond the visible spectrum. For example, an infrared (IR) sensor candetect the presence of heat whereas a UV sensitive detector candetermine the presence of a UV light source, such as the sun.

In one embodiment, the display can include a touch sensitive surfacethat can respond to objects incorporated into the protective cover. Thetouch sensitive surface can include a number of elements that can couplewith some or all of the plurality of objects on or near the protectivelayer of the display. The coupling can, for example, be capacitive innature and provide signals that can be evaluated by a processor in thetablet device. The signals can be used, for example, in controllingcertain aspects of the operation of the tablet device. In oneembodiment, the object, or objects, can take the form of electricallyconductive elements embedded in the flap of the protective cover. Inthis way, when the protective cover is brought near or into contact withthe protective layer of the display, the electrically conductiveelements can interact with the capacitive elements providing signals tothe processor.

The signals provided to the processor can correspond to a size,position, and shape of the electrically conductive objects. Therefore,the size, position, and shape of the electrically conductive objects canbe associated with information that can be used by the processor. Theinformation can, for example, be used by the processor to determineaspects of the protective cover based upon information associated withspecific configurations of the conductive objects. Accordingly, anynumber of characteristics of the objects such as the size, shape,orientation, position, etc. of the objects can be used to passivelyconvey information from the flap of the protective cover to theprocessor. This information can then be used by the processor to executeinstructions that can be used to carry out any number of operations bythe tablet device. The information can also be used to conveyinformation specific to the protective cover (such as type, color,style, specific serial number).

These and other embodiments are discussed below with reference to FIGS.1-16. However, those skilled in the art will readily appreciate that thedetailed description given herein with respect to these figures is forexplanatory purposes only and should not be construed as limiting.

The electronic device can take many forms. For the remainder of thisdiscussion, the electronic device is described in terms of a handheldportable computing device. Accordingly, FIG. 1 shows a top perspectiveview of electronic device 10 in accordance with the describedembodiments. Electronic device 10 can process data and more particularlymedia data such as audio, visual, images, etc. By way of example,electronic device 10 can generally correspond to a device that canperform as a smart phone, a music player, a game player, a visualplayer, a personal digital assistant (PDA), a tablet device and thelike. With regards to being handheld, electronic device 10 can be heldin one hand while being operated by the other hand (i.e., no referencesurface such as a desktop is needed). Hence, electronic device 10 can beheld in one hand while operational input commands can be provided by theother hand. The operational input commands can include operating avolume switch, a hold switch, or by providing inputs to a touchsensitive surface such as a touch sensitive display device or a touchpad.

Electronic device 10 can include housing 12. In some embodiments,housing 12 can take the form of a single piece housing formed of anynumber of materials such as plastic or non-magnetic metal which can beforged, molded, or otherwise formed into a desired shape. In those caseswhere electronic device 10 has a metal housing and incorporates radiofrequency (RF) based functionality, a portion of housing 12 can includeradio transparent materials such as ceramic, or plastic. Housing 12 canbe configured to enclose a number of internal components. The internalcomponents can be mechanical or structural used to provide support orthey can be operational/functional components that can provide aspecific set of operations/functions. For example, housing 12 canenclose and support various structural and electrical components(including integrated circuit chips) to provide computing operations forelectronic device 10. Examples of operational components can includeintegrated circuits, processors, memory, batteries, antennas, circuitry,sensors, display, inputs, and so on. The integrated circuits can takethe form of chips, chip sets, or modules any of which can be surfacemounted to a printed circuit board, or PCB, or other support structure.For example, a main logic board (MLB) can have integrated circuitsmounted thereon that can include at least a microprocessor,semi-conductor memory (such as FLASH), and various support circuits andso on. Examples of structural components can include frames, walls,fasteners, stiffeners, movement mechanisms (hinge), etc. Depending ontheir desired configuration, the components can be external (i.e.,exposed at the surface) and/or internal (e.g., embedded within housing).

Housing 12 can include opening 14 for placing internal components and asnecessary can be sized to accommodate a display assembly for presentingvisual content, the display assembly being covered and protected byprotective cover layer 16. In some cases, the display assembly can betouch sensitive allowing tactile inputs that can be used to providecontrol signals to electronic device 10. In some cases, the displayassembly can be a large prominent display area that covers a majority ofthe real estate on the front of the electronic device.

Electronic device 10 can include attachment features that correspondwith attachment features in an accessory device such as a protectivecover. In this way, the protective cover and electronic device 10 canattach to each other in a releasable manner. When attached to eachother, the protective cover and electronic device 10 can operate as asingle operating unit. On the other hand, in the detached mode, theprotective cover and electronic device 10 can act separately, and ifdesired, as two individual parts. The attachment between the protectivecover and electronic device 10 can be widely varied. For example, theprotective cover and electronic device 10 do not generally includeexternal visible attachment features that adversely affect the look andfeel or ornamental appearance (e.g., snaps, latches, etc.), but ratherattachment features that cannot be seen from the outside of theprotective cover or electronic device 10 and thus do not affect the lookand feel or ornamental appearance of the protective cover or electronicdevice 10. By way of example, the attachment features can be provided byattraction surfaces that do not disturb the external surfaces of theprotective cover or electronic device 10. In one embodiment, at least aportion of the attachment features utilize magnetic attraction toprovide some or all of the attaching force.

Accordingly, electronic device 10 can include magnetic attachment system18 and magnetic attachment system 20. Magnetic attachment system 18 canbe side mounted to housing 12 and be used to magnetically attachelectronic device 10 to an appropriately configured accessory such asthe protective cover. Magnetic attachment system 20 on the other handcan be located within opening 14 and beneath cover glass 16 and caninclude one or more of magnetic elements 22. In one embodiment, magneticelements 22 can be configured in a magnetic array (such as the Halbacharray) to enhance a magnetic field presented to a correspondingmagnetically compatible element in the protective cover. Magneticattachment system 20 can be positioned at various locations withinopening 14. For example, magnetic attachment system 20 can be positionedin proximity to side walls 12 c and 12 d. In this way, lateral movement(referred to as racking) of the protective cover while attached toelectronic device 10 can be substantially reduced.

It should be noted that magnetic elements 22 can affect magneticallysensitive circuits such as Hall Effect sensor 24 and magnetometercircuit 26 in the form of onboard compass 26. Therefore, in some cases,field shaping elements can be used to reduce magnetic affectsexperienced by such circuits. For example, field shaping magnets can beused to control the shape and extent of a magnetic field generated bymagnetic elements 22. In some cases, the shape and positioning ofmagnetic elements 22 can help to prevent magnetic flux leakage thatcould otherwise affect the sensitive magnetic circuits. For example,magnetic elements 22 can have a trapezoidal shape (or other appropriategeometry) well suited to reduce an amount of magnetic flux leakage thatcan affect, for example, on-board compass 26.

FIG. 2A and FIG. 2B show electronic device 10 presented in terms of aparticular embodiment in the form of tablet device 100 in relation to anaccessory device presented as protective cover 200 each in perspectivetop views. In particular, FIGS. 2A and 2B shows two perspective views oftablet device 100 and protective cover 200 in the open configuration.For example, FIG. 2A shows a magnetic surface provided by magneticattachment system 104 disposed in housing 102. FIG. 2B, on the otherhand, is the view presented in FIG. 2A rotated about 180° to provide asecond view of attachment feature 204 and its relationship withprotective cover 200.

Referring now to FIG. 2A, tablet device 100 can include housing 102 thatcan enclose and support magnetic attachment system 104. Tablet device100 can take the form of a particular member of a family of tabletcomputing devices such as the iPad™ manufactured by Apple Inc. ofCupertino, Calif. So as not to interfere with the magnetic fieldgenerated by magnetic attachment system 104, at least that portion ofhousing 102 nearest magnetic attachment system 104 can be formed of anynumber of non-magnetic materials such as plastic or non-magnetic metalsuch as aluminum. Magnetic attachment system 104 can be configured toprovide a variable magnetic surface at housing 102. The variablemagnetic surface can be in accordance with an attachment state ofmagnetic attachment system 104. For example, a first magnetic surfacecan have a magnetic strength value that is less than a first thresholdvalue and thus is unsuitable for creating a magnetic circuit capable offorming a suitable attachment and unsuitable for adversely affecting amagnetically sensitive device in proximity to tablet device 100. Thefirst magnetic surface can, therefore, be associated with magneticattachment system 104 being inactive.

In some embodiments, magnetic attachment system 104 can have movablemagnetic elements that can cause the magnetic surface to change from thefirst magnetic surface to a second magnetic surface that is suitable forforming and maintaining a magnetic attachment and is therefore active.In one embodiment, the movable magnetic elements can be held away fromhousing 102 in the inactive state and be impelled towards housing 102 inthe active state thereby causing the first magnetic surface totransition to the second magnetic surface consistent with magneticattachment system 104 transitioning from inactive to active,respectively.

In one embodiment, detectors disposed within housing 102 can determineif magnetic attachment system 104 is active or inactive. For example,when magnetic attachment system 104 includes movable magnetic elements,then a linear Hall Effect sensor can provide information that can beused to deduce the state of magnetic attachment system 104 by providingmagnetic field strength values and any changes thereof. With thosemagnetic attachment systems having movable magnetic elements, the dataprovided by the linear Hall Effect sensor can indicate relative positionof the movable magnetic elements and therefore if motion has occurred.Movement of the movable magnetic elements can also be detected using amore direct approach such as a tact switch that can directly detectmovement of the movable magnetic elements in magnetic attachment system104. Detectors that are displaced from magnetic attachment system 104(such as a magnetometer such as compass 26) can detect a change in alocal magnetic environment that can be correlated to the state ofmagnetic attachment system 104. For example, if compass 26 experiences amagnetic offset consistent with magnetic attachment system 104 beingactive (such as the magnetic offset being greater than a threshold),then it can be deduced that magnetic attachment system 104 is active andtablet device 100 and protective cover 200 are magnetically attached toeach other. This information can be used in addition to sensorinformation to deduce that if attached, protective cover 200 is in apartially open configuration with respect to tablet device 100.

Housing 102 can also enclose and support internally various structuraland electrical components (including integrated circuit chips and othercircuitry) to provide computing operations for tablet device 100.Housing 102 can include opening 106 for placing internal components andcan be sized to accommodate a display assembly or system suitable forproviding a user with at least visual content as for example via adisplay. In some cases, the display assembly can include touch sensitivecapabilities providing the user with the ability to provide tactileinputs to tablet device 100 using touch inputs. The display assembly canbe formed of a number of layers including a topmost layer taking theform of transparent cover glass 108 formed of polycarbonate or otherappropriate plastic or highly polished glass. Using highly polishedglass, cover glass 108 can substantially fill opening 106.

Although not shown, the display assembly underlying cover glass 108 canbe used to display images using any suitable display technology, such asLCD, LED, OLED, electronic or e-inks, and so on. The display assemblycan be placed and secured within the cavity using a variety ofmechanisms. In one embodiment, the display assembly is snapped into thecavity. It can be placed flush with the adjacent portion of the housing.In this way, the display can present visual content that can includevisual, still images, as well as icons such as graphical user interface(GUI) that can provide information the user (e.g., text, objects,graphics) as well as receive user provided inputs. In some cases,displayed icons can be moved by a user to a more convenient location onthe display.

Tablet device 100 can include camera assembly 110 arranged to capture animage or images. Tablet device 100 can also include ambient light sensor112 (ALS) used to detect a level of ambient light associated with cameraassembly 110. In one embodiment ALS 112 can be used to set a brightnesslevel of the display assembly. For example, in a darker environment withlittle ambient light, the readings from ALS 112 can cause a processor intablet device 100 to dim the display assembly. In a brighterenvironment, the display assembly can be made brighter. Tablet devicecan further include compass 114 used to detect external magnetic fieldsthat can help in the determination of a geographical location of tabletdevice 100. Moreover, a magnetically sensitive circuit (such as compass114) can be used to determine a state of magnetic attachment system 104by detecting a change in the local magnetic environment. This change canbe represented as a magnetic offset.

Tablet device 100 can also include Hall Effect (HFX) sensor 116 that canbe used to detect various properties of a corresponding magneticelement. In some embodiments, tablet device 100 can include more thanone HFX sensor and/or multiple HFX sensors of varying types. Forexample, tablet device 100 can include an HFX sensor to detect if cover200 is in the open or closed configuration. Tablet device 100 can alsoinclude a linear HFX sensor to detect angular displacement of magneticelements in flap 202. In this way, various magnetic properties such asmagnetic field strength (static and dynamic), magnetic field polarity,angular position of a magnet in relation to the sensor, can be used todetermine aspects of tablet device 100/cover 200. Other types of sensorscan include inertial sensors along the lines of an accelerometer andgyroscope (neither shown) can be used to determine any dynamic changesin the position and orientation of tablet device 100 in real time.

Protective cover 200 can include flap 202. In one embodiment, flap 202can have a size and shape in accordance with cover glass 108. Flap 202can be pivotally connected to hinge assembly 204 shown in FIG. 2B. Inthis way, flap 202 can rotate about pivot line 206. Hinge assembly 204can include a magnetic attachment feature 208. The magnetic attachmentforce between magnetic attachment feature 208 and magnetic attachmentsystem 104 can maintain protective cover 200 and tablet device 100 in aproper orientation and placement vis-a-vis flap 202 and cover glass 108.By proper orientation it is meant that protective cover 200 can onlyproperly attach to tablet device 100 having flap 202 and cover glass 108aligned in a mating engagement. The mating arrangement between coverglass 108 and flap 202 is such that flap 202 covers substantially all ofcover glass 108 when flap 202 is placed in contact with cover glass 108as shown in FIG. 3A. In this way, the flap 202 can be used as aprotective cover to protect aspects of electronic device 100. Flap 202can be formed of various materials such as plastic, cloth, and so forth.Since protective cover 200 can be easily attached directly to thehousing 102 without fasteners, flap 202 can essentially conform to theshape of tablet device 100. In this way, the cover 200 will not detractor otherwise obscure the look and feel of tablet device 100. Flap 202can be unitary in nature or flap 202 can be segmented in such a way thata segment of the flap can be lifted to expose a corresponding portion ofthe display. The number and size of the segments can be widely varied.Flap 202 can also include functional elements that can cooperate with acorresponding functional element in electronic device 100. In this way,manipulating flap 202 by, for example, lifting flap 202 (or a foldablesegment thereof) away from (or towards) a corresponding sensor canresult in an alteration in the operation of tablet device 100.

Flap 202 can include magnetic material. For example, magnetic elements210 can be used to magnetically attach to corresponding magneticattachment system 20 whereas magnetic element 212 can be detectable byHall Effect sensor 116 when flap 202 is in position above cover glass108. In this way, Hall Effect sensor 116 can respond by generating asignal that can be interpreted as information that can be used by aprocessor. The information can be used as cover positional informationby the processor, for example, to determine a relative spatial positionof flap 202 and tablet device 100. The relative spatial position can beused to alter an operating state of tablet device 100. Hall Effectsensor 116 (in the form of a linear Hall Effect sensor) can be used todetermine any dynamic changes in the detected magnetic field indicativeof movement of the magnet and tablet device 100 such as angulardisplacement of magnetic element 212 in relation to Hall Effect sensor116. In some embodiments, flap 202 can include more than one magneticelement 212 positioned in such a way as to be detectable bycorresponding HFX sensors 116 disposed in tablet device 100. In thisway, information related to folding of a segmented version of cover 200can be relayed to and used by tablet device 100. For example, bystaggering the respective positions of HFX sensors 116 and magneticelements 212 spatial relationship information between cover 200 andtablet device 100 can be deduced.

Cover 200 can include other magnets in the form of magnetic array 214.Magnetic array 214 can also be configured to convey information totablet device 100 for example, when tablet device 100 includes multipleHFX sensors that can detect magnetic array 214. In this way, informationin the form of a magnetic code can be provided to tablet device 100. Forexample, if magnetic array 214 includes four magnets, then fourcorresponding HFX sensors 116 can associate information with thepresence or absence of a particular magnet in magnetic array 214. Inthis way, an appropriately configured magnetic array pattern canrepresent information such as a color or style of protective cover 200.

Flap 202 can include other types of passive elements 216 in addition tomagnets that can take the form of capacitive elements 216 that can bedetected by a multi-touch (MT) sensitive layer incorporated in displayassembly when flap 202 is placed upon cover glass 108. In this way, theMT sensitive layer can respond to the presence of capacitive elements216 by generating a touch pattern consistent with the defined pattern.The defined pattern can be used to convey information to tablet device100. The information can include, for example, aspects andcharacteristics of protective cover 200 such as color, type, style,serial number, and so forth. In addition to passive elements, flap 202can include active elements 218 such as RFID device 218 that can be usedto identify protective cover 200. In particular, when protective cover200 is in the closed configuration, flap 202 can be in contact withcover glass 108 thereby allowing a RFID sensor within tablet device 100to “read” RFID device 218. In this way information about cover 200, suchas an identification of a serial number, style, date and place ofmanufacture, authentication code of protective cover 200, can also beretrieved.

Protective cover 200 can also include features that can be detectable byoptical sensors such as ALS or camera assembly. For example,micro-perforations 220 can be formed in protective cover 200 that canpermit selected amounts of light to penetrate protective cover 200 inthe vicinity of ALS 112 or camera assemblyl 10. Micro-perforations 220can be arranged in a pattern that can convey information to tablet 100.For example, micro-perforations 220 can be configured in a bar codearrangement that can provide information in the form of a specific lightsignal.

Although FIGS. 3A and 3B show protective cover 200 and tablet device 100magnetically attached to each other where any form of attachment betweenflap 200 and tablet device 100 is possible. For example, protectivecover 200 can be formed of a sleeve portion pivotally coupled to flap202. In this way, tablet device 100 can be inserted into the sleeveportion and flap 202 can then pivot to open and closed configurationswithout the need for magnetic attachment. However, for the remainder ofthis discussion and without loss of generality, it is presumed thatprotective cover 200 and tablet device 100 are magnetically attached toeach other.

FIG. 3A shows a magnetic attachment embodiment in which protective cover200 is in a closed configuration such that cover glass 108 is fullycovered by and in contact with flap 202. Protective cover 200 can pivotabout hinge assembly 206 from the closed configuration of FIG. 3A to anopen configuration of FIG. 3B. In the closed configuration, inner layerof flap 202 can come in direct contact with cover glass 108. In thisway, passive elements 208 can be detected by a corresponding detectioncircuit disposed in tablet device 100. For example, if passive elements208 include capacitive elements, then a multi-touch (MT) circuitdisposed within the display assembly beneath cover glass 108 can detectand “read” capacitive elements 216. In this way, capacitive elements 216can be used to convey information about protective cover 200. Forexample, information encoded in a pattern of capacitive elements 216 canbe detected by the MT circuit and information passed to the processor.The processor, in turn, can read the pattern of capacitive elements 216as a signature that can be used to identify various characteristics ofprotective cover 200. The patterns can be widely varied. A first patterncan maximize a difference in capacitive signal between any two adjacentcapacitive elements in order to maximize a signal to noise ratio andthereby improve the reading ability of the MT circuit.

For example, capacitive elements 216 can take the form of metallicstrips placed diagonally with respect to a Cartesian detection griddisposed beneath cover glass 108. In this way, by associating a specificinformation element (such a binary “1”) with a particular orientation, acorrelated pattern of metallic strips can be used to passively conveyinformation to the processor in tablet device 100. It should be noted,however, that the need to maximize a differential signal betweenadjacent capacitive elements can be achieved by varying not only theorientation, but size, shape, material (by varying the electricalproperties of the various capacitive elements) and so forth.

FIG. 4 shows a top view of a specific embodiment of protective cover 200in the form of segmented cover assembly 400. It should be noted that thenumber of segments can be widely varied. For example, as shown in FIG.4, the number of segments is four. However, in other embodiments (asshown in FIG. 5, for example) the number of segments can be three whilein other embodiments (such as FIG. 2) the number of segments can be one(i.e.; unitary flap).

Cover assembly 400 can include body 402. Body 402 can have a size andshape in accordance with cover glass 108 of tablet device 100. Body 402can be formed from a single piece of foldable or pliable material. Body402 can also be divided into segments separated from each other by afolding region. In this way, the segments can be folded with respect toeach other at the folding regions.

In one embodiment, body 402 can be formed layers of material attached toone another forming a laminate structure. Each layer can take the formof a single piece of material that can have a size and shape inconformance with body 402. Each layer can also have a size and shapethat correspond to only a portion of body 402.

In a specific embodiment, segmented body 402 can be partitioned into anumber of segments 404-410 interspersed with thinner, foldable portions412. Each of the segments 404-410 can include one or more insertsdisposed therein (not shown) that can be formed of rigid or semi-rigidmaterial adding resiliency to body 402. Examples of materials that canbe used include plastics, fiber glass, carbon fiber composites, metals,and the like. Segment 404 can accommodate magnetic attachment system414. Magnetic attachment system 414 can include magnets 416 some ofwhich can interact with magnets in table device 100 and morespecifically with magnets 22 in attachment feature 20. Magnets 416 canmagnetically interact with magnets 22 to secure cover 400 to tabletdevice 100. However, magnets 416 can also be used to form a triangularsupport structure by forming a magnetic circuit with magneticallyattractable element 418. In one embodiment, magnets 22 can be arrangedin a magnetic array along the lines of a Halbach array in order toenhance a magnetic field from magnets 416. The enhanced one sided natureof the magnetic field provided by the Halbach array is well suited forenhancing magnetic attraction. For example, magnets 416 arranged as aHalbach array can pass substantially more magnetic flux to magneticelement 418 and essentially no magnetic flux passing through an exteriorsurface of cover 400. In this way, magnetic attracting force betweenmagnets 416 and magnetically attractable element 418 can becommensurably increased while eliminating any magnetically relatedaffects external to cover 400.

Cover 400 can also include magnetic elements 210 that can be used tomagnetically attach to corresponding magnetic attachment system 20 toreduce racking of cover 400 when attached to tablet device 100. Cover400 can also include magnetic element 212 that can be used to activateHall Effect sensor 116 when flap 402 is in position above cover glass108. Cover 400 can also include passive or active elements thatcomplement sensors disposed within tablet 100. For example, cover 400can include magnetic array 214 that can be configured to conveyinformation to tablet device 100 for example, when tablet device 100includes multiple HFX sensors that can detect magnetic array 214. Inthis way, information in the form of a magnetic code can be provided totablet device 100 Cover 400 can also include passive elements 216 (suchas capacitive elements 216) that can be read by capacitive basedmulti-touch circuitry disposed within tablet 100. Cover 400 can alsoinclude active elements such as RFID based elements 218. In addition,cover 400 can be configured to include light transmitting features thatcan provide a light signal to camera assembly 110 or ALS 112. Lighttransmitting features can include patterned micro-perforations that passlight in a pattern that can be read by camera assembly 110 or ALS 112.

FIG. 5 shows a top view of another embodiment of protective cover 200 inthe form of cover assembly 500. Cover assembly 500 can include body 502.In the embodiment shown in FIG. 5, segmented body 502 can be partitionedinto three segments, segments 504, 506, and 508 each coupled to anadjacent segment by thinner, foldable portions 510. Each of the segments504-508 can include one or more inserts disposed therein that can beused to provide structural support for segmented body 502. That is, theinserts can provide stiffness to the cover assembly. In some cases, theinserts may be referred to as stiffeners. As such, cover assembly 500 isrelatively stiff except along the foldable regions that are thinner anddo not include the inserts (e.g., allows folding) making segmented coverassembly 500 more robust and easier to handle. In one embodimentsegments 504, 506, and 508 can have a size relationship to each othersuch that a segments 504-508 can be used to form a triangular supportstructure.

In one embodiment, segmented body 502 can include a number of magnetssome of which can be used to form the triangular structure. For example,segment 504 can include first edge attach magnets 512 linearly arrayedalong first edge 514 of segmented body 502 whereas segment 508 caninclude second edge attach magnets 516 linearly arrayed along secondedge 518 opposite to first edge 514. In this embodiment, first edgeattach magnets 512 and second edge attach magnets 516 have a one to onecorrespondence in which each first edge attach magnet 512 can beassociated with a corresponding one of second edge attach magnets 516.For example, first edge attach magnet 512-1 can have polarity P1 thatcan be associated with second edge attach magnet 516-1 having polarityP2 where first edge attach magnet 512-1 and second edge attach magnet516-1 are about the same size and magnetic strength. In this way, thetriangular structure can be formed without the need for a separatemagnetically attractable element (such as magnetically attractableelement 418) since the triangular structure can be formed using amagnetic edge attach technique. The magnetic edge attach techniquerelies upon the first and second edge attach magnets when brought intoproximity with each other (and not necessarily overlaying each other) toform a magnetic circuit. The magnetic circuit can provide a suitablemagnetic attractive force to maintain the triangular structure in aproper configuration.

Cover 500 can also include magnetic elements 210 that can be used tomagnetically attach to corresponding magnetic attachment system 20 toreduce racking of cover 500 when attached to tablet device 100. Cover500 can also include magnetic element 212 that can be used to activateHall Effect sensor 116 when body 502 is in position above cover glass108. Cover 500 can include magnetic array 214 that can be configured toconvey information to tablet device 100 using, for example, multiple HFXsensors that can detect magnetic array 214. Cover 500 can include otherpassive elements such as capacitive elements 216 that can be read bycapacitive based multi-touch circuitry disposed within tablet 100. Cover500 can also include active elements such as RFID based elements 218 andas with cover 400, cover 500 can be configured to include lighttransmitting features (such as patterned micro-perforations) that canprovide a light signal to camera assembly 110 or ALS 112.

FIG. 6A and FIG. 6B shows segmented cover 400 in partial openconfigurations with respect to tablet device 100 whereas FIG. 6C showssegmented cover 500 in a correspondingly similar partial openconfiguration. It should be noted that the following describing cover400 can also be applied to cover 500 since both are foldable and havemultiple segments. By partial open configuration it is meant that due tothe segmented nature of segmented cover 400 (or cover 500), only aportion of protective layer 108 can be exposed at a time. However, inorder for tablet device 100 to operate in a suitable manner consistentwith a folded configuration of cover 400, the processor in tablet device100 must be able to accurately determine a spatial relationship betweencover 400 and tablet device 100 in real time.

For example, as shown in FIG. 6A, in those situations where HFX sensor116 cannot detect a magnetic field from magnets 416, there are threespatial relationships between cover 400 and tablet device 100 consistentwith that scenario. Possible state (1) is that cover 400 and tabletdevice 100 are not magnetically attached to each other, possible state(2) is that cover 400 is magnetically attached to tablet device 100 butin a fully open configuration, or possible state (3) is that cover 400is attached to tablet 100 and in at least a first partially open, orfirst peek mode state. Therefore, in order to resolve this problem,other sensors and their associated data can be used. For example, inorder to resolve possible state (1), a determination can be made ifmagnetic compass 114 is experiencing a magnetic offset consistent withthat expected when magnetic attachment system 104 is active. Thismagnetic offset can be due to magnets in tablet device 100 as well asthe presence of magnets in magnetic attachment system 204. If themagnetic offset is consistent with no attachment (i.e., a baselinemagnetic offset) then the situation has been resolved to configurationstate (1), namely no magnetic connection and the processor can causetablet device 100 to operate accordingly (the display assembly is fullyviewable and can fully present visual content over its entire displayarea). Other sensors can also be used to help resolve the connectionstatus of tablet device 100. The other sensors can include a HFX sensordisposed in proximity to magnetic attachment system 104 as well assensors (such as a linear Hall Effect sensor, tact switch, etc.) thatcan resolve movement of movable magnetic elements in magnetic attachmentsystems that rely on moving magnets to transition from inactive toactive state.

If, however, is has been resolved that tablet device 100 and cover 400are magnetically attached to each other, then either state (2) or state(3) is still possible. In order to resolve this situation, additionalsensors and the associated data can be used. For example, if ALS 112 orcamera assembly 110 cannot detect a least a minimum amount of light,then it can be precluded that the segment 406 (or segment 506 in cover500) is blocking the light and therefore remains in position overlayinga corresponding portion of cover glass 108. Therefore, the processor candeduce that only segment 404 is lifted and exposing correspondingportion 602 of cover glass 108 in what can be referred to as first peekmode. Other sensors that can be used include additional Hall Effectsensors disposed along either edges 12 b or 12 c of housing 12 that candetect corresponding magnets in segments 404-410. Once the processor hasdetermined that cover 400 is in a first peek mode folded configuration,the processor can direct tablet 100 to present visual content at onlyportion 602 of the display assembly.

On the other hand, if ALS or camera assembly 110 can detect at least theminimum amount of light, then still other sensors can be used to resolveif cover 400 is fully open or in an extended peek mode (shown in FIG.6B). For example, if an HFX sensor disposed in tablet device 100 candetect a corresponding magnet in segment 408, then the processor candeduce that segment 408 is in place over a corresponding portion ofcover glass 108 and cover 400 is in an extended peek mode folded statealong the lines of FIG. 6B. On the other hand, if the HFX sensor doesnot detect the magnet (or any magnet in segment 410), then the processorcan deduce that cover 400 is in a fully open configuration and directtablet device 100 to present visual content accordingly.

In addition to magnets, patterns of capacitive elements in thosesegments (such as segments 406, 408, 410) that remain in contact withcover glass 108 can be detected and used by the processor to resolve thefolding state of cover 400. The capacitive elements in segment 406 beingdetected is a clear indication that segment 406 is in contact with coverglass 108. However, since HFX sensor 116 is no longer detecting themagnetic field from magnetic elements 416, the processor in tabletdevice 100 can deduce that only segment 404 is lifted while all othersegments remain in contact with cover glass 108 and cover 400 is in thefirst peek mode configuration.

Using this information, the processor can alter an operating state oftablet device 100 in accordance with a folded state of cover 400. Forexample, the processor can display information, such as battery level,time of day, email, etc. only in that portion 602. Information detectedin segment 406 can also be used by tablet device 100 to present specificvisual content on portion of the display assembly that presents visualcontent in viewable portion 602. For example, tablet device 100 todisplay visual information suitable only for presentation by viewableportion 602 in a manner in accordance with available presentationresources. For example visual elements (such as icons, graphical userinput, and video) can be processed in a manner in accordance with thesize and number of pixels available for presentation. The visualelements can include information icons related to email received,weather conditions and so forth. In one embodiment, visual presentationresources (such as a number of pixels available for presenting video orstill images) can be consistent across either cover 400 or cover 500.For example, in order to provide a consistent user experience, the sizeof segment 404 and segment 504 can be such that in the first peek mode,that the same number of pixels are available as presentation resources.In this way, tablet device 100 is not required to comprehend aparticular configuration (3 fold or 4 fold) to present visual content inthe first peek mode.

FIG. 6B shows another partially open situation where in addition tosegment 404, segment 406 has also been lifted. The determination thatonly segments 404 and 406 can be ascertained when it is determined inone embodiment that capacitive elements 216 in segment 406 are no longerdetected whereas capacitive elements 216 in segment 408 can be detected.In this way, additional display resources can be enabled to provide anenhanced display experience. In addition to using capacitive elements,other sensors can be brought into play. For example, ALS 112 and cameraassembly 110 can be used separately or in combination to determine thatsegment 408 has been lifted based upon amounts of ambient light detected(in the case of ALS 116) and/or periodic image capture events by cameraassembly 112. As discussed above, a magnetometer can be used todetermine the attachment state (active or inactive) of magneticattachment system 104. In this way, the processor can use thisinformation to distinguish between peek and extended peek mode. In stillanother embodiment, elements 604 can be placed on the periphery ofsegmented cover 400 at selected locations that correspond with detectionnodes in tablet device 100. In this way, the ability to detect elements604 by the detection nodes can provide a further indication of thestatus of segmented cover 400 in relation to tablet device 100.

As shown in FIG. 6C, as discussed above, in the first peek mode, tabletdevice 100 can present visual content in the form of icons 620. Hence,information in the form of visual content such as time of day, notes,and so forth can be presented for viewing on only that portion ofdisplay viewable. Once the sensors detect that segment 506 has beenplaced back on glass layer 108, tablet 100 can return to the previousoperational state such as a sleep state. Furthermore, in anotherembodiment, when an icon arranged to respond to a touch is displayed,then that portion of a touch sensitive layer corresponding to thevisible portion of the display can also be activated. As above, theamount of visual presentation resources (pixels, etc.) can be the samefor both tablet device 100 when used with cover 400 or cover 500. Inother words, the size of segments 404 and 504 are such that the amountof visual presentation resources corresponding to portions 602 and 622are about the same.

FIG. 7A illustrates tablet device 100 operating in the first peek modewhen selected icons 702 or other visual elements can be displayed onlyin viewable portion 704 of display 16 of tablet device 100. Icons 702can be simply display type icons or in some instances, some or all oficons 702 can be user interactive. For example, icon 702-1 can display aclock showing the current time whereas icon 702-2 can representgraphical user interfaces used to modify operations of a media playerfunction performed by tablet device 100. Other icons can include, icon702-3 representing current weather conditions, icon 702-4 representing astock market result, and so on. FIG. 7B, on the other hand, illustratessecond peek mode in which additional functionality can be enabled whenit is determined that more than a pre-determined amount of display 16 isviewable. In this mode, additional information available in portions ofprotective cover 700 in contact with display 16 can cause tablet device100 to alter its operating state along the lines disclosed. For example,in an advanced peek mode, an additional display area that is viewablecan be used to present video 704 (with overlaid user interface 702-2 orequivalent), textual data 706 and so on.

It should be noted that icons and iconic behavior can be modified inaccordance with an amount of viewable display. For example, anotification icon can be presented indicating that the tablet device isoperating in peek or associated mode. In addition, properties of an iconin the form of a graphical user interface, or GUI, for example, can berelated to the amount of display that is viewable. For example, in afirst peek mode, the size of a GUI can expand or contract depending uponan amount of display that is viewable. Moreover, other properties suchas number of pixels, pixel density, placement in a visual field, and soon can be related to peek mode as well as the speed of peek mode. Byspeed of peek mode it is meant that the time it takes for the tabletdevice to alter its operating state to a corresponding peek mode state.In one example, as a portion of the cover is lifted, visual contentpresented at the display can track the cover as it is lifted going fromfirst peek mode, to second peek mode (if the lifting is continuous) andall the way to fully open all during a continuous movement of the cover.

FIG. 8 shows system 800 that includes protective cover 400 pivotallycoupled to tablet device 100 in accordance with the describedembodiments. In this embodiment, at least one segment 404-410 caninclude passive elements 216 that can take the form of capacitiveelements arranged in various patterns. Each pattern can encodeinformation in the form of data. For example, when detectable by an MTcircuit in tablet device 100, an alternating diagonal arrangement ofcapacitive elements can maximize a signal to noise ratio. In this way,capacitive elements 802 can be conductive in nature and can take theform of metallic strips (formed of, for example, aluminum) that areincorporated into segment 404 in an alternating diagonal pattern inrelation to detection nodes in tablet device 100 in order to maximum thereliability of detection. For example, at least some of diagonalmetallic strips 802 can be arranged at about 45° in relation to acapacitive detection grid disposed in tablet device 100. The capacitiveelements can vary from one segment to another and even vary from withineach segment. In this way, information can be encoded in any number ofdifferent ways by using various configurations of capacitive elements.

FIG. 9 shows system 900 being a more generalized version of system 800in which various information elements are shown. For example, cover 400can include magnetic array 902 arranged in a pattern that can bedetected by magnetic sensors 904 disposed in tablet device 100. Magneticarray 902 can encode information that can be used to identify variousaspects of cover 400. For example, when magnetic sensors 904 can resolvea magnetic field from each member of magnetic array 902, then at least 4units of information can be encoded. For example, if magnetic array 902include 3 magnets in positions first, second and fourth positions, thenthe detection of a magnet by a corresponding one of magnetic sensor 904can be resolved as an information unit (such as “1”). In this example,magnetic array 902 having magnets in first, second, and fourth positionscan be resolved by magnetic sensors 904 as data word {1,1,0,1} that canbe used to identify four information states related to cover 400 (suchas color, style, etc.). In some cases, additional information states canbe encoded if magnetic sensors 904 can resolve magnetic polarities ofeach of magnetic array 902. In still other embodiments, the relativemagnetic field strength of the constituent magnets in magnetic array 902can also be used to encode information.

Positional information can be provided by arranging elements (such asmagnets 906) in such a way as to be detectable by corresponding sensors908 disposed in tablet device 100. For example, when magnets 906 arepositioned in one or more of segments 404-410, then magnetic sensors 908disposed in tablet device 100 can detect a corresponding one of magnets906 when that segment incorporating the magnet overlays cover glass 108.In this way, tablet device 100 can use this information to resolve aspatial relationship between cover 400 and tablet device 100. Forexample, if Hall Effect sensor 908-1 does not detect magnet 906-1, andHall Effect sensor 908-2 does detect magnet 906-2, then tablet device100 can deduce that cover 400 is in a first partially open configurationwhere only segment 404 is folded away from cover glass 108. Similarly,when sensor 908-3 cannot detect magnet 906-3 but an attachment sensor(such as sensor 910) confirms that tablet 100 and cover 400 are attachedto each other, then tablet device 900 can deduce that cover 400 is in anextended folded configuration where segments 404, 406 and 408 are foldedaway from tablet 100. In this configuration, tablet device 100 canoperate in an extended peek mode by presenting visual content theviewable portion of the display assembly (that portion of the displaythat is overlaid by segments 404-408 when cover 400 is in a fully closedconfiguration).

In addition to detecting magnets in cover 400, magnetic sensor 910 canbe used to detect a state of magnetic attachment system. For example, iftablet device 100 has a magnetic attachment system that uses movablemagnetic elements, then magnetic sensor 910 can detect a current localmagnetic environment. The processor in tablet device 100 can determineif the current local magnetic environment is consistent with the movablemagnets being in an active or inactive state. If the current localmagnetic environment is one consistent with the magnetic attachmentsystem being active, then the tablet device can deduce that cover 400 isattached to tablet 100 and operate according to a folded configurationof cover 400.

Additional resources can include optical resources 912. In oneembodiment, optical resources 912 can take the form of a pattern ofmicro-perforations that can allow light to pass through cover 400 toreach either or both of camera assembly 110 and ALS 112. This patterncan take the form of, for example, bar code 914 that can encodeinformation related to cover 400. Still further, active elements such asRFID tag 916 can be detected by corresponding circuitry 918 disposed intablet device 100.

FIG. 10 shows a flowchart detailing process 1000 in accordance with thedescribed embodiments. Process 1000 can be performed by receiving at atablet device a no magnet detect signal at 1002 from a first magneticsensor (such as a Hall Effect sensor) indicating the magnetic sensor hasnot detected a magnetic field corresponding to a magnet disposed in aprotective cover. At this point, the tablet device must deduce if thecover is attached and if so the folded configuration of the cover. At1004, a magnet is detected signal is received from a second HFX sensorindicating the cover is attached. The tablet device uses the informationprovided by the first HFX sensor and the second HFX sensor incombination to determine at 1006 that the cover is in a first foldedconfiguration. The tablet device presents visual content in accordancewith a first peek mode consistent with the first folded configuration ofthe cover at 1008.

FIG. 11 shows a flowchart detailing process 1100 in accordance with thedescribed embodiments. Process 1100 can be performed by receiving asignal at 1102 from a magnetic sensor (such as a Hall Effect sensor)indicating that a magnet disposed in a cover is not detected. At 1102,the processor in the tablet device responds to the received signal byactivating an optical system disposed in the tablet device at 1104. Theoptical system can include image capture devices such as a camera or aphoto detector device such as an ambient light sensor (ALS). At 1106, adetermination is made if light is detected. If at 1106, it is determinedthat light is detected and at 1108 a magnet is detected signal isreceived by the tablet device, the cover is in a second foldedconfiguration at 1110 and the tablet device presents visual informationin accordance with a second peek mode at 1112. The second peek modebeing an extended peek mode in which additional portions of a displayare viewable and presenting visual content.

Returning back to 1106, if the optical system does not detect light,then at 1114, the cover is in the first folded configuration and at1116, the tablet device presents visual content in accordance with thefirst peek mode. It should be noted that in in addition to detectinglight, other embodiments describe using images on an underside of thecover that can be detectable by the optical system. In this way, theoptical system can confirm that by capturing the image that at least acorresponding portion of the cover is in contact with the tablet device.

FIG. 12 shows a flowchart detailing process 1200 in accordance with thedescribed embodiments. Process 1200 can be performed by receiving magnetnot detected signal from a magnetic sensor at 1202 by the tablet device.At 1204, the processor in the tablet device responds to receipt of thenot detected signal by evaluating a local magnetic environment. In oneembodiment, the local magnetic environment can be evaluated using amagnetometer and determining a magnetic offset value at 1206. If at 1206a magnetic offset value is determined to be not consistent with a covermagnetically attached to the tablet device, then the cover is notmagnetically attached to the tablet device at 1208 and process 1200ends. On the other hand, if the magnetic offset is consistent with thecover being magnetically attached to the tablet device, then a magnetdetected signal is received at 1210, and the cover is in the firstfolded configuration at 1212 and the tablet presents visual content inaccordance with the first peek mode at 1214.

FIG. 13 shows state peek mode state diagram 1300 in accordance with thedescribed embodiments. It should be noted that although peek mode statediagram shows three tablet device operating states (standard, firstpeek, second peek), the number of operating states can be related insome embodiments to the number of foldable segments. For example, if nrepresents the number of foldable segments, then there can be n−1 peekmodes available (assuming that there is adequate sensor resources forthe tablet device). Moving on to FIG. 13, a tablet device can operate ina standard operating mode at 1302 when the tablet device determines thata foldable cover is in either the open configuration or the closedconfiguration. In the open configuration (1304), the display assemblypresents present visual content without restriction. In the closedconfiguration (706), the display assembly is prevented from presentingany visual content.

When the tablet device is in the standard mode (1302) and a firstsegment (represented as “S1”) is lifted, then the tablet devicedetermines that only the first segment is lifted and changes to firstpeek mode operating state (1308). In the first peek mode operatingstate, any visual content presented by the display assembly is limitedto that portion of the display assembly that is determined to beviewable consistent with the first segment being lifted. In first peekmode, when the first segment is no longer lifted from the tablet device,then the tablet device returns to standard mode (1302) and moreparticularly, the closed configuration. However, when the tablet deviceis in the first peek mode (1308) and the first segment (“S2”) isdetermined to be lifted by the tablet device, then the tablet devicechanges to a second peek mode (1310). In the second peek mode, visualcontent is presented by the display assembly in only that portiondetermined to be viewable.

When the tablet device determines that the first segment is not lifted,then the tablet device transitions from the second peek mode to thefirst peek mode. Also, when tablet device is in the second peek mode andthe tablet device determines that both segments are not lifted, then thetablet device transitions directly from second peek mode to standardmode consistent with foldable cover being in the closed configuration.Conversely, the tablet device can transition directly from the standardmode consistent with the closed configuration when first and secondsegments are both lifted concurrently. Also in the second peek mode, thetablet device can transition directly to the standard mode consistentwith foldable cover being in the open configuration when all remainingsegments of the cover are lifted.

It should also be noted, that applications can be executed in accordancewith the current operating state of the tablet device. For example, anapplication running in first peek mode can immediately transition to asecond peek mode (and vice versa). In the case of an email application,a full version of an email message can be presented in the standardmode, a smaller version (possibly just a pre-defined summation) in thesecond peek mode, and only a subject line in the first peek mode. Itshould be appreciated that a user can provide peek mode settings whichcan determine how tablet device responds to the cover being positionedin a manner consistent with a peek mode.

FIG. 14 shows a flowchart detailing process 1400 in accordance with thedescribed embodiments. Process 1400 can be carried out by performing atleast the following operations by a tablet device associated with afoldable cover. In the described embodiment, process 1400 can start at1402 by determining if the foldable cover is closed with respect to thetablet device. By closed it is meant that the protective cover iscovering and therefore in proximity to a multi-touch (MT) detection griddisposed within the tablet device. For example, when the tablet deviceincludes a display, the display can include MT functionality inaccordance with the MT detection grid. Moreover, the determination ifthe cover is closed or not can be resolved in any suitable manner. Forexample, an optical sensor can detect the presence, or not, of theprotective cover based upon an amount of light detected and based uponthe amount of light deduce whether or not the foldable cover is closedor open.

In any case, once it is determined that the foldable cover is closed, adetermination is made at 1404 if a pattern of information elements isdetected. In one embodiment, the information elements can storeinformation capacitively based upon size, orientation, shape, and soforth of the information elements and the MT detection grid. The patternof information elements can, therefore, be based upon a correlation ofindividual characteristics of each of the information elements. Forexample, when the information element is a diagonal strip of aluminum, arightward tilt can be associated with “1”, whereas a leftward tilt canbe associated with “0”, and vice versa. When a pattern is detected, thenat 1406, a determination is made if the pattern is recognized or not.When the pattern is not recognized, then process 1400 ends, otherwise,at 1408, the recognized pattern is associated with foldable coverinformation. The foldable cover information can include, for example,color, style, manufacture date and location, and so forth. At 1410, thefoldable cover information can then be stored in a data storage devicein the tablet device for future reference. For example, if part of thefoldable cover information includes a serial number, then the serialnumber can be associated with a database of authorized foldable coversthat can be periodically stored and updated in the data storage devicein the tablet device. If the foldable cover serial number does not matchan authorized serial number, then the presumption is that the cover isnot authenticated.

FIG. 15 shows a flowchart detailing process 1500 in accordance with adescribed embodiment that begins at 1502 when the tablet device receivesa magnet detected signal from a first magnetic sensor indicating thatthe cover is in a fully closed configuration. More specifically, process1500 begins at 1502 by receiving the indication from the HFX sensor thatthe state of the cover is closed. At 1504, a multi-touch (MT) sensordisposed in the tablet device detects a MT event. The MT event can be aresult of capacitive element disposed with the cover. The capacitiveelements can be arranged in a specific pattern used to encodeinformation. At 1506, a determination is made if the informationassociated with the capacitive pattern corresponding to the MT eventmatches an signature stored in the tablet device. If the MT signature isdetermined to be consistent with the stored signature, then at 1108, thetablet device authenticates the cover at 1110, otherwise, the tabletdevice determines that the cover is not authenticated at 1112.

FIG. 16 is a block diagram of an electronic device 1600 suitable for usewith the described embodiments. The electronic device 1600 illustratescircuitry of a representative computing device. The electronic device1600 includes a processor 1602 that pertains to a microprocessor orcontroller for controlling the overall operation of the electronicdevice 1600. The electronic device 1600 stores media data pertaining tomedia items in a file system 1604 and a cache 1606. The file system 1604is, typically, a storage disk or a plurality of disks. The file system1604 typically provides high capacity storage capability for theelectronic device 1600. However, since the access time to the filesystem 1604 is relatively slow, the electronic device 1600 can alsoinclude a cache 1606. The cache 1606 is, for example, Random-AccessMemory (RAM) provided by semiconductor memory. The relative access timeto the cache 1606 is substantially shorter than for the file system1604. However, the cache 1606 does not have the large storage capacityof the file system 1604. Further, the file system 1604, when active,consumes more power than does the cache 1606. The power consumption isoften a concern when the electronic device 1600 is a portable mediadevice that is powered by a battery 1624. The electronic device 1600 canalso include a RAM 1620 and a Read-Only Memory (ROM) 1622. The ROM 1622can store programs, utilities or processes to be executed in anon-volatile manner. The RAM 1620 provides volatile data storage, suchas for the cache 1606.

The electronic device 1600 also includes a user input device 1608 thatallows a user of the electronic device 1600 to interact with theelectronic device 1600. For example, the user input device 1608 can takea variety of forms, such as a button, keypad, dial, touch screen, audioinput interface, visual/image capture input interface, input in the formof sensor data, etc. Still further, the electronic device 1600 includesa display 1610 (screen display) that can be controlled by the processor1602 to display information to the user. A data bus 1616 can facilitatedata transfer between at least the file system 1604, the cache 1606, theprocessor 1602, and the CODEC 1613.

In one embodiment, the electronic device 1600 serves to store aplurality of media items (e.g., songs, podcasts, etc.) in the filesystem 1604. When a user desires to have the electronic device play aparticular media item, a list of available media items is displayed onthe display 1610. Then, using the user input device 1608, a user canselect one of the available media items. The processor 1502, uponreceiving a selection of a particular media item, supplies the mediadata (e.g., audio file) for the particular media item to a coder/decoder(CODEC) 1613. The CODEC 1513 then produces analog output signals for aspeaker 1614. The speaker 1614 can be a speaker internal to theelectronic device 1600 or external to the electronic device 1600. Forexample, headphones or earphones that connect to the electronic device1600 would be considered an external speaker.

The electronic device 1500 also includes a network/bus interface 1611that couples to a data link 1612. The data link 1612 allows theelectronic device 1500 to couple to a host computer or to accessorydevices. The data link 1512 can be provided over a wired connection or awireless connection. In the case of a wireless connection, thenetwork/bus interface 1611 can include a wireless transceiver. The mediaitems (media assets) can pertain to one or more different types of mediacontent. In one embodiment, the media items are audio tracks (e.g.,songs, audio books, and podcasts). In another embodiment, the mediaitems are images (e.g., photos). However, in other embodiments, themedia items can be any combination of audio, graphical or visualcontent. Sensor 1626 can take the form of circuitry for detecting anynumber of stimuli. For example, sensor 1526 can include a Hall Effectsensor responsive to external magnetic field, an audio sensor, a lightsensor such as a photometer, and so on.

The various aspects, embodiments, implementations or features of thedescribed embodiments can be used separately or in any combination.Various aspects of the described embodiments can be implemented bysoftware, hardware or a combination of hardware and software. Thedescribed embodiments can also be embodied as computer readable code ona non-transitory computer readable medium. The computer readable mediumis defined as any data storage device that can store data which canthereafter be read by a computer system. Examples of the computerreadable medium include read-only memory, random-access memory, CD-ROMs,DVDs, and optical data storage devices. The computer readable medium canalso be distributed over network-coupled computer systems so that thecomputer readable code is stored and executed in a distributed fashion.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of the specificembodiments described herein are presented for purposes of illustrationand description. They are not target to be exhaustive or to limit theembodiments to the precise forms disclosed. It will be apparent to oneof ordinary skill in the art that many modifications and variations arepossible in view of the above teachings.

The advantages of the embodiments described are numerous. Differentaspects, embodiments or implementations can yield one or more of thefollowing advantages. Many features and advantages of the presentembodiments are apparent from the written description and, thus, it isintended by the appended claims to cover all such features andadvantages of the invention. Further, since numerous modifications andchanges will readily occur to those skilled in the art, the embodimentsshould not be limited to the exact construction and operation asillustrated and described. Hence, all suitable modifications andequivalents can be resorted to as falling within the scope of theinvention.

What is claimed is:
 1. An accessory device, comprising: a flap, the flapincluding at least a passive information element associated withaccessory device information; and an attachment mechanism configured forreleasably attaching the accessory device and an electronic device, theelectronic device comprising: a processor, a display, an attachmentdetection mechanism configured to detect that the accessory device isattached to the electronic device, and a passive information detectionmechanism that is enabled to (1) detect the presence of the passiveinformation element, and (2) receive information from the passiveinformation element only when the attachment detection mechanismprovides an indication that the accessory device and the electronicdevice are attached to each other.
 2. The accessory device as recited inclaim 1, wherein the processor uses the information received from thepassive information element to alter an operating state of theelectronic device.
 3. The accessory device as recited in claim 2, theelectronic device comprising a multi-state magnetic attachment system,wherein in an active state the multi-state magnetic attachment systemprovides a first magnetic surface suitable for magnetically attachingthe accessory device and the electronic device.
 4. The accessory deviceas recited in claim 3, the attachment detection mechanism comprising: asensor configured to detect when the multi-state magnetic attachmentsystem is in the active state.
 5. The accessory device as recited inclaim 4, the sensor comprising a Hall Effect sensor.
 6. The accessorydevice as recited in claim 5, the multi-state magnetic attachment systemas recited in claim 5 comprising a housing secured to an interiorsurface of the electronic device, and a movable magnet, wherein themovable magnet moves from a first location in an inactive state to asecond position at the interior surface of the electronic device whenthe multi-state magnetic attachment system is active.
 7. The accessorydevice as recited in claim 6, wherein the Hall Effect sensor detects thechange in position of the movable magnet.
 8. The accessory device asrecited in claim 1, wherein passive information element is a capacitiveelement, the capacitive element detectable by the passive informationdetection mechanism in the form of a multi-touch sensing circuitdisposed in the display.
 9. The accessory device as recited in claim 8,the multi-touch sensing circuit is enabled to detect the capacitiveelement only when the Hall Effect sensor detects that the magneticattachment system is in the active state.
 10. A method for altering anoperating state of an electronic device having a processor in accordancewith accessory device information associated with an accessory device,comprising: detecting a passive information element in the accessorydevice by a detection mechanism in the electronic device; determiningthe accessory device information in accordance with the detecting by theelectronic device; and altering the operating state of the electronicdevice in accordance with the accessory device information by theprocessor.
 11. The method as recited in claim 10, wherein the accessorydevice information includes any of an accessory type, an accessorycolor, an accessory identification number, and an accessory style. 12.The method as recited in claim 11, wherein the accessory is a protectivecover.
 13. The method as recited in claim 12, wherein the passiveinformation element is a conductive pattern characterized as havingconductivity diagonal to the detection mechanism.
 14. The method asrecited in claim 13, wherein the conductive pattern includes at leastone metallic strip.
 15. The method as recited in claim 10, wherein thedetection mechanism is a self-capacitance multi-touch based detectionmechanism.
 16. The method as recited in claim 15, wherein the electronicdevice includes a sensor arranged to indicate a spatial relationshipbetween the accessory device and the electronic device.
 17. The methodas recited in claim 16, wherein the sensor detects the accessory devicebeing in a closed configuration with respect to the electronic device.18. Non-transitory computer readable medium for altering an operatingstate of an electronic device having a processor in accordance withaccessory device information associated with a passive informationelement incorporated into the accessory device, comprising: computercode for detecting the passive information element by a passiveinformation element detection mechanism; computer code for determiningthe accessory device information in accordance with the detecting; andcomputer code for altering the operating state of the electronic devicein accordance with the accessory device information.
 19. The computerreadable medium as recited in claim 18, wherein the accessory deviceinformation includes any of an accessory type, an accessory color, anaccessory identification number, and an accessory style.
 20. Thecomputer readable medium as recited in claim 19, wherein the passiveinformation element is a conductive pattern characterized as havingconductivity diagonal to the detection mechanism.
 21. The computerreadable medium as recited in claim 20, wherein the conductive patternincludes at least one metallic strip.
 22. The computer readable mediumas recited in claim 18, wherein the detection mechanism is aself-capacitance multi-touch based detection mechanism.
 23. An accessorydevice, comprising: a flap; an attachment mechanism for attaching theaccessory device to an electronic device having a display and aprocessor, the flap having a size and shape in accordance with thedisplay; an information element incorporated into the flap, theinformation element being associated with accessory device information,wherein when the information element is detected by a detectionmechanism in the electronic device only when the flap and the displayare in close proximity to each other, the detection mechanism providesthe accessory device information to the processor, the processor usingthe accessory device information to alter an operating state of theelectronic device.
 24. The accessory device as recited in claim 23,wherein the passive information element is a conductive patterncharacterized as having at least some conductivity in a directiondiagonal to the detection mechanism.
 25. The accessory device as recitedin claim 24, wherein the conductive pattern includes at least twocorrelated conductive strips at least one of which is oriented diagonalto the detection mechanism.